We provide biostatistics expertise for a number of NIEHS and NTP researchers, as well as researchers at universities and other government agencies who are conducting research related to the mission of the NIEHS. In these collaborations, we provide advice about study design, analyze data, interpret statistical results, and coauthor papers for publication. We have a long-standing collaboration with Dr. Dixon's laboratory, which is researching leiomyomas (uterine fibroids). In the studies published this year, genomic characteristics of the tumor tissue, signaling pathways and effects of cadmium exposure on leiomyoma cell cultures were investigated. We analyzed data in a study of reproductive endpoints and metabolic parameters of mice exposed to arsenic and showed that arsenic had adverse effects at doses lower than previously demonstrated. In collaboration with the NTP, we analyzed data from two human studies of bisphenol A (BPA) and related compounds. In one study, we documented pharmacokinetics properties of BPA orally consumed by volunteers. In a second study, we examined blood and urine concentrations of BPA and two related compounds in cashiers who handled thermal receipt paper, which contains BPA or one of two substitutes for BPA. In several surveys of U.S. and international research institutions, we characterized several aspects of research ethics policies including: authorship, conflict of interest, research misconduct and publication retraction.